Smoking causes serious respiratory system diseases and cancer, though it is hard to persuade the smokers to completely quit smoking.
Nicotine is the effective ingredient in cigarettes. Nicotine acts on the receptor of the central nervous system.
Nicotine is a micromolecular alkaloid, which is basically harmless to human bodies at a small dosage. Plus, its half life period is extremely short in blood. Tar is the major harmful substance in tobacco. Tobacco tar comprises several thousands of ingredients, dozens of which are carcinogenic substances.
To provide cigarette substitutes that contain nicotine but not harmful tar, many products have been used. These products are not as harmful as tar, but are absorbed very slowly. As a result, smokers can't be satisfied in full. In addition, the smokers are deprived of the “smoking” habit.
The electronic cigarettes currently available on the market may resolve the above-mentioned issue, though they are complicated in structure. They don't provide the ideal aerosol effects, and their atomizing efficiency is not high.